Georgian Nikoloz Basilashvili ousted third-seeded Andrey Rublev of Russia 7-6 (1), 6-4 on Monday in the first round at the Terra Wortmann Open in Halle, Germany.
Rublev fired 10 aces but won just 26.9 percent of his second serves as Basilashvili won in one hour, 25 minutes.
No. 6 Pablo Carreno Busta of Spain advanced with a 6-3, 7-6 (5) win over Holger Rune of Denmark.
Laslo Djere of Serbia, Ugo Humbert of France, Ilya Ivashka of Belarus and Mackenzie McDonald of the U.S. also advanced to the Round of 16.
A pair of seeded Americans and the third-seeded hometown favorite were all shown early exits on the grass courts in London.
Grigor Dimitrov of Bulgaria rallied to defeat No. 3 Cameron Norrie of Great Britain 6-7 (2), 6-1, 6-4 in one hour, 58 minutes. British wild card Jack Draper breezed past No. 4 Taylor Fritz 6-3, 6-2, and Australian Alex de Minaur dispatched No. 8 Reilly Opelka 6-4, 6-4.
Seventh-seeded Marin Cilic of Croatia ousted British wild card Liam Broady 6-1, 4-6, 7-5.
Alexander Bublik of Kazakhstan and Alejandro Davidovich Fokina of Spain also advanced.
–Field Level Media